A Digital Rumor Should Never Lead to a Police Raid

If police raided a home based only on an anonymous phone call claiming residents broke the law, it would be clearly unconstitutional.

Yet EFF has found that police and courts are regularly conducting and approving raids based on the similar type of unreliable digital evidence: Internet Protocol (IP) address information.

In a whitepaper released today, EFF challenges law enforcement and courts’ reliance on IP addresses, without more, to identify the location of crimes and the individuals responsible. While IP addresses can be a useful piece of an investigation, authorities need to properly evaluate the information, and more importantly, corroborate it, before IP address information can be used to support police raids, arrests, and other dangerous police operations.

IP address information was designed to route traffic on the Internet, not serve as an identifier for other purposes. As the paper explains, IP addresses information isn't the same as physical addresses or license plates that can pinpoint an exact location or identify a particular person. Put simply: there is no uniform way to systematically map physical locations based on IP addresses or create a phone book to lookup users of particular IP addresses.

Law enforcement’s over-reliance on the technology is a product of police and courts not understanding the limitations of both IP addresses and the tools used to link the IP address with a person or a physical location. And the police too often compound that problem by relying on metaphors in warrant applications that liken IP addresses to physical addresses or license plates, signaling far more confidence in the information than it merits.

Recent events demonstrate the problem: A story in Fusion documents how residents of a farm in the geographic center of America are subjected to countless police raids and criminal suspicion, even though they’ve done nothing wrong. A story in Seattle’s newspaper The Stranger described how police raided the home and computers of a Seattle privacy activist operating a Tor exit relay because they mistakenly believed the home contained child pornography. And these are just two stories that found their way into the media.

These ill-informed raids jeopardize public safety and violate individuals’ privacy rights. They also waste police time and resources chasing people who are innocent of the crimes being investigated.

The whitepaper calls on police and courts to recalibrate their assumptions about IP address information, especially when it is used to identify a particular location to be searched or individual to be arrested. EFF suggests that IP address information be treated, in the words of the Supreme Court, as more like “casual rumor circulating in the underworld,” or an unreliable informant. The Constitution requires further investigation and corroboration of rumors and anonymous tips before police can rely upon them to establish probable cause authorizing warrants to search homes or arrest individuals. The same should be true of IP address information.

The paper also explains why the technology’s limitations can make it unreliable and how the Supreme Court’s rules around unreliable information provided by anonymous informants should apply to IP address information in warrant applications. The paper concludes with two lists of questions to ask and concrete steps to take: one for police and one for judges. The goal is to better protect the public so that the misuse of IP address information doesn’t lead to a miscarriage of justice.

We hope the whitepaper can serve as a resource for law enforcement and courts while also triggering a broader conversation about IP address information’s use in criminal investigations. In the coming months, EFF hopes to discuss these concerns with law enforcement and courts with the goal of preventing unwarranted privacy invasions and violations of the Fourth Amendment. We also hope that our discussions will result in better law enforcement investigations that do not waste scarce police resources. If you are a law enforcement agency or court interested in this issue, please contact info@eff.org.

Related Updates

In today's Star Tribune, renowned computer security expert Bruce Schneier explains in plain language why the NSA spying program is a remarkably ineffective way to identify potential threats. He hypothesizes an "unrealistically accurate system" for data mining personal information and demonstrates that it would generate billions of false alarms...

Technician Describes Secret NSA Room at AT&ampT Facility San Francisco - AT&ampT has set up a secret, secure room for the NSA in at least one of the company's facilities -- a room into which AT&ampT has been diverting its customers' emails and other Internet communications in bulk -- according...

Evidence For Illegal Spying Case Will Remain Under Seal for Now San Francisco - A federal judge in San Francisco ruled today that the Electronic Frontier Foundation (EFF) can use critical evidence in its class-action lawsuit against AT&ampT. However, U.S. District Judge Vaughn Walker said the evidence -- three documents...

This morning we had the first court hearing in EFF's class-action lawsuit against AT&T. Over AT&T's objection, the court refrained from closing the courtroom and denied AT&T's bid to force us to return the AT&T documents supporting our Motion for a Preliminary Injunction. While keeping the documents under seal...

Wednesday's Arguments on Sealed Documents Set for 10am San Francisco - The judge in the Electronic Frontier Foundation's (EFF's) class-action lawsuit against AT&ampT denied a request for a conference today about closing the courtroom from reporters and spectators for tomorrow's hearing in the case, set to begin at 10 a.m...

This week members of over twenty civil liberties groups -- including the the Bill of Rights Defense Committee, the ACLU, href="http://www.checksbalances.org/">Patriots to Restore Checks and Balances, EPIC and the href="http://www.libertycoalition.net/">Liberty Coalition -- are calling Congress to demand action over the...

Telecom Giant Wants to Keep Public Away from Document Debate San Francisco - Lawyers for AT&ampT alerted the Electronic Frontier Foundation (EFF) today that it intends to ask the judge to close the courtroom in Wednesday's hearing in EFF's class-action lawsuit. EFF will oppose the request. EFF's suit accuses AT&ampT...

DOJ Intervention Comes Just Days Before Hearing on Sealed Evidence San Francisco - Early Saturday morning, the United States government filed a motion to dismiss the Electronic Frontier Foundation's (EFF's) class-action lawsuit against AT&ampT for illegally handing over its customers' telephone and Internet records and communications to the National Security...

Editor and Publisher has published an informative critique of the Washington Post's early poll in the wake of USA Today's report last week that three major telcos have violated the privacy of millions of ordinary Americans as part of the National Security Agency's (NSA's) spying program. Calling...

Early Saturday morning, in the darkest hours of the night, the Department of Justice made good its threat to file a motion to dismiss our class-action lawsuit against AT&T, contending that AT&T's collaboration with the NSA's massive and illegal program to wiretap and data-mine Americans' communications (which violates...